Lawton's engrossing sixth entry but the first chronologically in his Inspector Troy thriller series (Black Out, etc.) chronicles the major events leading up to WWII--Germany's annexation of Austria, Chamberlain's peace efforts, Kristallnacht--while providing a disturbing picture of anti-Semitism and class frictions in England at the time. As part of Scotland Yard's murder squad, Insp. Frederick Troy investigates a series of slayings of London rabbis, but various subplots equally intrigue, notably one that unfolds in an internment camp for Germans, Jews and foreigners--including Troy's Austrian-born brother, Rod--rounded up after Britain's entry into the war. At one point, Troy and a lady friend discover the "aphrodisia of war" in Hyde Park, a spot popular with couples for copulation during the blitz. Lawton does a fine job of incorporating such lesser known period details into his saga, though some readers may find he relies too often on deus ex machina for their taste.